This invention relates to a machine for separating cards, such as are used in packaging and the like, from the scrap of paperboard sheets from which they have been die cut, except for small integral connecting tangs. The cards may be box blanks or backing cards for blister packaging or any other type of card which is made by die cutting paperboard sheets. Often, the paperboard blank sheets are printed and then transported to an elevator and moved by elevator into a feeder and then into a die cutting machine. From the die cutting machine, they are transferred by means of a conveyor away from the machine to a storage or separator station.
The separating operation of the prior art has been widely performed by mechanically forcing scrap from the plane of the sheet. With the advent of mass produced packaging cards for wide distribution of consumer goods, however, a more rapid and economical manner of separating the cards from the sheet scrap has been desirable. One attempt at solving this problem is illustrated in U.S. Pat. No. 3,807,610, issued to Arthur R. Mueller, Jr. Apr. 30, 1974 and its parent patent U.S. Pat. No. 3,670,939 issued June 20, 1972. Various other stripping machines also have been developed over the years, but they have not been effective or economical because of their propensity to jam, when on occasion, the integral tangs holding the partially severed cards and blanks together did not fully tear. Moreover, other prior art designs to hold the scrap required "corking" about the die projections within the punching and stripping apparatus to insure the stripping of the paperboard cards from the scrap.
The present invention is the result of a unique mechanical and electrical combination which permits elimination of many heavy mechanical moving elements such as mechanical gripper bar assemblies that have been traditional in the die cut sheet stripping machines of the prior art.